Scratch - Uranus Explorer 2 {Scratch}

Scratch Uranus Explorer 2 Original Design / Scratch Built

Scratch - Uranus Explorer 2 {Scratch}

Contributed by Tom Markel

Construction Rating:
Flight Rating:
Overall Rating:

Published:	2011-08-14
Manufacturer:	Scratch
Style:	Ring/Tube/Cone Fin

Brief

Personal Challenge: A workin' model built from and themed on Toilet Paper Rolls, Rear Ejection (of course!) and fly-able with C engines

Components

8 High-Quality Toilet Paper Roll Centers*
BT 5
BT 20
Foam Board t' make Adapter Rings
Maskin' Tape (lots and lots o' Maskin' Tape)
Rubber Bands for Shock Cord
Standard 12 inch parachute

(*Regardin' "High Quality Toilet Paper Rolls," t' cores from t' industrial strength extra large rolls used in hospitals and office buildings by professional janitorial services are thicker, ya bilge rat, smoother, and tougher than t' stuff you get at t' grocery store. T' spirals are however very deep.)

Construction

Challenge: Build a rocket based on theme o' Uranus Explorer (but keep it PG rated)

At t' same time I be buildin' t' rocket (actually t' second rocket, me bucko, ya bilge rat, shiver me timbers, t' Uranus Explorer 1 was a dismal failure) I be makin' up a story that went along with t' rocket. Well, blow me down! I think t' best place t' put that is up front in this review, so here it is.

INTERSPACE TELEX FROM SPACE COMMAND

URGENT: You have been ordered t' take IMMEDIATE command o' t' Uranus Explorer II.

BACKGROUND: In t' first half o' t' 21st century, arrr, concerns on Earth mounted regardin' global warming. Blimey! While thar was a great uproar about changin' human behavior t' combat this menace, arrr, t' problem solved itself in t' second half o' t' century. While t' well-meanin' efforts o' t' "Greens," as they came t' be called, may have had some impact, t' finite supplies o' fossil fuels expired by 2075. Begad! In addition, t' fight t' obesity epidemic, t' fast grub enterprises were vilified by t' population. Ronald McDonald was hung in effigy in several countries. Since beef hamburgers were t' main stock in trade for these restaurants, t' demand for beef largely expired with t' fast grub franchises. Aye aye! Arrr! T' final major source o' greenhouse gasses, me bucko, t' cattle farms, also went t' way o' t' dinosaur. Avast! Arrr! T' global warmin' scare be over.

T' loss o' cheap fuel and fast foods led t' a progressive sense o' dissatisfaction among t' people o' Earth, who attempted t' drown their sorrows in entertainment. Well, blow me down! VCRs and DVD players gave way t' IPods, Androids, matey, Playstations, Wiis, and other devices, all o' which shared two features. Begad! Avast, me proud beauty! First, matey, arrr, they required electricity. Begad! Second, me bucko, arrr, they were a mindless waste o' time.

To replace t' fossil fuels, t' people o' Earth maximized their use o' renewable energy sources, me hearties, includin' Wind, Geothermal, me hearties, matey, Hydroelectric, and Solar. Begad! T' first three were largely limited by geography. Solar, arrr, however, shiver me timbers, was only limited by surface area. Ya scallywag! By t' year 2125, me bucko, solar "farms" had sprung up over much o' t' Earth’s surface, includin' Antarctica, shiver me timbers, me hearties, and floatin' solar "mats" covered much o' t' oceans. Low Earth Orbit solar satellites created a virtual "traffic jam" in t' skies, t' t' chagrin o' terrestrial astronomers. Arrr! Lookin' up at t' sky at night, more stars "moved" than remained in once place.

T' combination o' t' loss o' greenhouse gas generators and t' impact o' solar collectors shadin' much o' Earth’s surface as well as fillin' t' skies had an effect that should have been anticipated--- t' Earth's climate was headin' for a second Ice Age. Temperatures plummeted.

Many different plans t' restore t' greenhouse gas "blanket" were attempted. Begad! Begad! A nationwide chili marathon was probably t' most grandiose. It had little effect on t' global atmosphere, matey, matey, but resulted in numerous hospitalizations throughout t' state o' Texas dues t' t' accumulation o' noxious gases. In desperation, shiver me timbers, t' people o' Earth looked t' t' skies for help. Begad! T' United States, arrr, once an importer o' fossil fuels, arrr, me hearties, now developed a plan t' import greenhouse gases from space.

Of t' four planetary gas giants, me bucko, t' highest concentrations o' methane are found around Uranus, me hearties, matey, at roughly 2% o' t' atmosphere by volume. Ya scallywag! While further away than Saturn and Jupiter, shiver me timbers, manned expeditions t' Uranus in 2186 found t' planet had a rocky core with numerous central caverns. Ahoy! Concentrations o' methane within t' caverns approached 75%. Aye aye! Unlike Saturn and Jupiter, t' caverns could be sealed, shiver me timbers, cleared o' t' methane, me hearties, heated, me bucko, and pressurized. In other words, matey, thar could be life inside Uranus.

Drillin' operations began in 2192, shiver me timbers, and t' planet was formally colonized under t' leadership o' Admiral Ezekiel Koli in 2199. Blimey! Well, blow me down! T' fecundity o' E. Ya scallywag! Aye aye! Koli's descendents became legendary, me hearties, and within 5 years t' colonists had spread throughout t' bowels o' t' planet. Aye aye! Methane gas generated within t' rocky core was diverted t' natural "vents" on t' planet surface. Well, blow me down! Well, blow me down! This gas was collected in Surface Repositories (dubbed "SuPositories.") T' SuPositories were then harvested by tanker ships and t' gas be transported t' Earth. T' effort has been thus far successful. Earth's temperatures have stabilized and are gradually returnin' t' 21st century levels. Avast! Aye aye! T' only casualty was t' state o' Utah, matey, which seceded from t' Union when t' restoration o' "normal" temperatures forced them t' abandon plans for year-round skiing.

Durin' t' drillin' operations on Uranus, shiver me timbers, miners discovered rich deposits o' Amodium. Avast, me proud beauty! Aye aye! Existin' in two chemical isomers, t' "L" or levo form and t' "D" or dextro form, arrr, me bucko, shiver me timbers, Uranian Amodium was predominantly in t' D isomer. Valued for its medical properties, arrr, Amodium-D is extremely useful in t' treatment o' dysentery. Begad! Ya scallywag! Earth's Amodium supplies were exhausted in t' early 21st century in a vain attempt t' stem t' tide o' large fecal outflows from Washington, D.C. Uranus produces 80% o' t' pharmaceutical grade Amodium-D in t' solar system. T' only other major supply o' Amodium-D is in t' asteroid belt. Blimey! Tanker ships, matey, notorious for poor hygiene, matey, shiver me timbers, were plagued with dysentery and t' production o' Amodium around Uranus rivaled t' methane minin' operations in profitability.

T' growin' population inside Uranus yearned for t' same amenities and distractions as their distant Earthly cousins. Entrepreneurs, shiver me timbers, ever anxious t' make a credit, me hearties, arrr, established venues on t' Uranian satellites, includin' a Disney Theme Park, arrr, arrr, "Part o' Your World," on t' satellite Ariel, arrr, a Lane Bryant Woman's Clothin' outlet store on t' satellite Titania, shiver me timbers, and a romantic bed and breakfast getaway, "A Quiver o' Love" on t' satellite Cupid. Arrr! Begad! By 2250, matey, Uranian commerce had established a respectable amount o' regularity.

Unfortunately, t' hygienic habits o' t' Tanker ship crews did nay improve. Due t' failure in interspace decontamination procedures, me bucko, one or more tankers have carried a type o' "animal fungus" from t' asteroids t' t' surface o' Uranus. Ya scallywag! These vile creatures reproduce rapidly and are incredibly adherent t' t' rock and ice surface o' t' Uranian core. Aye aye! Avast! They are particularly attracted t' t' relative heat around t' vents o' Uranus. Dubbed, "Cling-Ons" by t' colonists, t' invaders have destroyed t' SuPositories and have multiplied t' t' extent that they are now obstructin' many o' t' methane outlets. Aye aye! T' buildup o' pressure behind t' vents is reachin' dangerous levels, me hearties, producin' dyspepsia, me hearties, nausea, ya bilge rat, and vomitin' among t' population o' t' planet. Arrr! Minin' operations o' Amodium-D have ground t' a halt. Aye aye! Because thar be no local supply, an outbreak o' dysentery on t' satellite Oberon has required importation o' Amodium from t' asteroid belt. Begad! This has put an incredible load on an already strained interplanetary supply system.

T' situation is now CRITICAL.

We have deployed Remotely Operated Infrared Detectors (ROIDs) within all t' major vents t' monitor t' situation. Ya scallywag! T' ROIDs will detect focal temperature increases which herald obstruction. Begad! Additional SuPositories have been prepared t' replace those destroyed by t' Cling-Ons. Ahoy! T' Jovian and Saturnine Fleets have been redirected t' assist in t' emergency.

T' initial scout ship, me bucko, t' Uranus Explorer, me bucko, was mothballed in 2195. Blimey! It has been recommissioned for t' rescue effort. Well, blow me down! Avast! T' previous BVD-1 subspace engine has been upgraded t' t' BVD-2. Blimey! T' ship has also been augmented by 4 Procto and Gamble Sharmin "Ultra" outboard engines t' give it interplanetary capability at 0.25 light speed.

Your mission is as follows:

Rendezvous with t' USS Colon Powell (commanded by Admiral Sigmoid Koli) and guide t' Fleets in t' evacuation o' Uranus.
Scour Uranus and wipe out t' Cling-Ons.
Monitor t' ROIDs. Well, blow me down! At any hint o' sensitivity, ya bilge rat, insert t' replacement SuPositories t' relieve t' obstructed vents.
Restore Amodium-D minin' operations, arrr, ya bilge rat, t' reduce t' frequency and urgency o' the runs betwixt t' asteroids and Uranus.

Addendum: On successful completion o' this mission, you and your spouse are authorized a 30 day furlough at t' "Quiver o' Love" on Cupid. Aye aye! Arrr! Remember, with 27 satellites, thar be always a full moon around Uranus.

END TRANSMISSION

Back t' t' review. Arrr! Goals o' t' rocket buildin' were as follows:

Had t' look at least slightly cool
Use Toilet Paper rolls for much or all o' construction
Rear End Ejection (naturally)
Inexpensive project
Standard (A, matey, B, ya bilge rat, or C) Engine size (see #4)
Write a background story.

After buildin' t' Estes Porta-Pot Shot, shiver me timbers, and readin' notes from a reviewer who suggested a rear-ejection model, started t' think o' other designs sort o' on t' same theme. Original design became t' Uranus Explorer 1 (UE1), (which will be fairly similar t' t' UE2, described here. Ya scallywag! Ahoy! I found that usin' only two rolls for t' nose-cone fuselage combo resulted in a stubby rocket that I could nay get stable (I know, I built it and tried. Arrr! For some reason Tim Van Milligan doesn't have Toilet Paper tubes in t' RockSim inventory. Ya scallywag! Ahoy! Go figure!) So t' lengthen t' fuselage, had t' use two rolls connected (alternative would have been t' use a single paper towel roll, but that would have violated t' theme. Avast! Avast! Would have had t' call it t' Brawny or t' Scrubber, or somethin' else. Begad! But I digress...) You say, no problem, ya bilge rat, a coupler would work for this. Problem, since I pre-determined t' use aft end ejection, me hearties, I needed a pristine smooth inner contour, so a (standard) internal coupler wouldn't work. Blimey! Arrr! So I went with an external coupler. Arrr! Begad! This o' course be aerodynamically suboptimal, shiver me timbers, arrr, but since I wasn't plannin' t' set an altitude or duration records, arrr, was acceptable. Ya scallywag! So I used an external coupler cut from another tube. I figured I would put t' launch lug in t' gap later (had I really thought it through, matey, me hearties, would have remember I could hide a launch lug in t' tube fins.) This still left a small step-off or "transition" on t' inside where t' two tubes butted together. Well, me bucko, blow me down! I ran maskin' tape from end t' end along t' inside so that thar were no transitions t' trap or catch t' engine pod and recovery devices durin' aft ejection.

Next problem: t' nose cone. Arrr! Ahoy! First, shiver me timbers, nay sure that toilet paper roll centers really come in a standard size for nose cones. Aye aye! Second, shiver me timbers, I'm cheap. Third, arrr, ya bilge rat, wanted t' keep overall weight o' t' body o' t' rocket light (more on this later.) 4rth, wanted t' use as many TP rolls as possible. Ya scallywag! Wondered---- how could I make a nose cone out o' a toilet paper roll?

By cuttin' 16 length-wise cuts nearly t' t' end o' t' roll, me hearties, me bucko, then cuttin' a diagonal out o' each section, matey, ya bilge rat, I be able t' create a roughly Ogive cone. Begad! Avast! Connected t' tips with tape. Put a "shoulder" (again cut from another TP roll) on t' anterior end o' t' body tube. Attached this with CA t' t' previous two tubes I now have a fuselage (one-piece with t' nose cone) just under three TP rolls long I then ran strips o' maskin' tape LENGTHWISE from just beyond t' tip t' just aft/tailward o' t' nose-cone/fuselage joint). Aye aye! Begad! Blimey! At t' tip, ya bilge rat, shiver me timbers, I cut the corners steeply and wrap around t' nose cone. Ahoy! I had t' run a few spiral wraps for support and t' maintain shape.

Nose Cone

Shoulder

Nose Cone/Fuselage

Finishing

As mentioned, t' buildin' and paintin' run together as t' paintin' be done before completely fittin' together t' parts.

Once I had t' shape roughed out, shiver me timbers, it be time t' fill. However, me bucko, I wanted t' have a clean paint job with different colors for t' fuselage and t' tube fins. Arrr! Aye aye! I felt that maskin' would be tough. Blimey! But if I painted them first, matey, matey, then I would be tryin' t' glue together painted surfaces. Avast, me proud beauty! Avast! That didn't sound like it would be t' strong. Avast! On t' other hand, I KNEW exactly where all t' joints would be (I was usin' four tube fins, paired, shiver me timbers, on opposite sides o' t' fuselage. Begad! Ya scallywag! Since 6 tubes would fit perfectly, arrr, I just placed marks at 60 degrees, 120 degrees, 240 degrees, and 300 degrees on t' fuselage. On t' tube fins, matey, ya bilge rat, two marks each, shiver me timbers, 60 degrees apart, would suffice. For increased stability, I let 1/2 o' t' tube fins lag behind t' end o' t' fuselage (also thought would look cooler. Blimey! Later durin' actual preparation o' t' rocket for launch I found it did make access t' t' engine mount awkward.) So marked on all t' tubes where t' joints should be. Begad! I also marked where I wanted t' put t' launch lug.

I wanted t' "protect" t' joint areas from t' paint and sealer t' set up a stronger joint. Begad! Blimey! On t' UE1 I had placed thin strips o' maskin' tape over these areas. I discovered t' maskin' tape broke down under t' sandin' process, so I tried Mylar tape strips, shiver me timbers, 1/4 inch wide. I placed a "tail" over t' edge/lip o' each tube, and then wrapped t' very tip INSIDE t' tube. Well, blow me down! Turned out t' sandin' still wore off most o' t' tails, shiver me timbers, but t' tip piece wrapped inside be an adequate marker for removal o' t' tape later. Blimey! Blimey! Each strip was 1/2 t' length o' a single tube.

It took five coats/sandings o' Elmer's filler t' get a good smooth surface over t' nose-cone maskin' tape. Well, me bucko, blow me down! Blimey! Therefore regardin' "savin' money" as a reason t' make your own nose cone--Unless your time is worth less than 25 cents an hour, you’re better off buyin' it from Tim. Begad! Blimey! But since this WAS a themed rocket, it seemed worth it. (Although me lovely wife wasn't happy about t' pile o' filler dust on t' front porch!) I need three coats/sandin' t' fill t' DEEP VALLEYS o' t' toilet paper roll spirals anyway, (another reason t' use REAL body tubes.) I sealed t' tube fins (outside only) t' same way.

Note that since this is a rear-ejection model, me hearties, it allowed me t' cover t' nose-cone/fuselage joint. Avast, me proud beauty! Arrr! Blimey! While I was fillin' in t' maskin' tape defects and t' tube spirals, me hearties, shiver me timbers, it turns out I had enough filler t' cover t' external coupler. Ya scallywag! In fact, by t' time I was done t' slight residual "bulge" be hardly notice-able. Blimey! (Performance-minded rocketeers are probably shudderin' at t' added weight o' t' filler required t' accomplish THAT.)

When I was finished, I had a very nice fuselage with a smooth surface from tip t' tail, me hearties, except for t' "break" in t' external coupler where I planned t' put t' launch lug. Begad! Again, had I been thinking, arrr, I would have filled this in too and put hidden t' lug in t' tube fin/fuselage joint. Avast! Well, blow me down! I believe t' absence o' a nose-cone/fuselage transition gives t' rocket a retro Buck Rogers look. Begad! O' course, ya bilge rat, me bucko, I also believe in t' tooth fairy. Begad! Again, I digress......

I knew that tryin' t' fill in t' INSIDE spirals o' t' tube fins was goin' t' be hopeless. Begad! Blimey! I figured t' insides o' a spaceflight engine would probably look a little "charred", me bucko, so I planned on paintin' t' inside flat black and hoped that would hide t' defects.

Okay, so paintin' now comes before actually completin' construction. Well, blow me down! Blimey! Before starting, arrr, I peeled back t' edges o' t' Mylar at t' distal edges o' t' tubes, shiver me timbers, arrr, t' make sure I could find them after paintin' (paintin' t' inside would obscure t' "tails" I had wrapped on t' inside o' t' tube.) T' hard part be FINDING t' edge. Begad! Blimey! Many o' t' "tails" that I had thought would provide "handles" had been sandin' off durin' finishing. But t' tips that I had wrapped on t' inside (unsealed) part o' t' tubes were still there. Usin' them as guides, arrr, I used an Exacto knife t' peel back t' edges o' t' Mylar tape on t' OUTSIDE so I could find it after paintin' t' inside. Ahoy! Blimey! Begad! Blimey! I wrapped newspaper around t' OUTSIDE o' t' tube fins, tapin' it at t' edges/lips. Avast, me proud beauty! Blimey! Begad! Blimey! Then I used flat black paint t' finish t' INSIDE o' t' tubes. I actually tried rolled up sandpaper t' reduce t' "nap" inside t' tube, ya bilge rat, but it didn't work very well. Aye aye! Blimey! Primer would have helped, shiver me timbers, but I be havin' a struggle justifyin' tryin' t' prime t' INSIDE o' t' engines. Avast, me proud beauty! Blimey! Again, I figured I was goin' for style, nay performance, arrr, so I gave up on that part. Begad! Blimey! I sort o' liked t' internal "charred" look o' t' engines. Blimey! Blimey! As a prior Air Force guy, I noticed t' nozzles o' jet engines on t' flight-line often had blackened look, matey, so I felt I was okay with it for space engines.

Color Scheme: All t' pictures o' t' PLANET Uranus showed it t' be a bluish color, so I figured I'd stay with this.

I primed t' fuselage with Krylon White Primer, three coats, with light sandin' betwixt coats. This filled in t' few defects I had left after t' Filler. Well, blow me down! I used Krylon True Blue for t' fuselage - I really like t' color this gave, me hearties, and I was happy with t' finish here.

After paintin' t' inside o' t' tube fins black, arrr, I took off t' outer maskin' paper. Begad! I then rolled up paper INSIDE t' tubes t' mask t' insides. Ya scallywag! This allowed me t' "stack" t' tubes, me bucko, which actually made paintin' t' outside easier. Aye aye! Arrr! I had run out o' primer, me bucko, matey, me bucko, so I went directly t' paintin' t' outside o' t' tubes Blue Ocean Breeze. Avast! I did 3 coats, matey, with a light sandin' betwixt coats. Blimey! Begad! I liked this color as well. Although I hadn't thought it out ahead o' time, I remember t' three colors that were common for bathroom tiles in t' 60s--- pastel yellow, pastel pink, arrr, and pastel blue. Begad! Ya scallywag! This looked pretty close t' t' pastel blue, arrr, connectin' t' planetary and Toilet Paper theme.

Moment o' truth, me bucko, ya bilge rat, what would happen when I peeled off t' Mylar? Actually, I be quite pleased with t' sharp edges. Begad! Well, blow me down! Pullin' t' tape off also raised some more "nap" off t' cardboard tubes, ya bilge rat, exactly what I wanted t' "rough it" for gluing.

As I had expected, despite t' masking, ya bilge rat, thar was a little bleedin' o' black and blue (no pun intended) at t' edges o' t' tube fins. Ya scallywag! I used thin strips o' silver Mylar tape t' cover/accent t' edges here and at t' trailin' end o' t' fuselage. Well, blow me down! As a USAFA grad, t' silver and blue together got me right under t' old squadron patch, shiver me timbers, as me Dad, a retired AF Navigator/Bombardier says. I wrapped t' edges o' t' tape into t' inside o' t' tube. Lookin' back, me bucko, this gave t' edge a bit o' a rough look; I probably would just have put it on t' OUTSIDE only, matey, ya bilge rat, shiver me timbers, just up t' t' edge.

Now that this was finished, me bucko, time t' see how things fit together. Avast! Begad! I used medium CA t' glue 4 tubes into two tube-fin pairs, arrr, placin' t' glue along one o' t' "naked" strips previously covered by Mylar. Layin' t' tubes flat gave me a good alignment. I then matched up t' remainin' strips on each tube pair with t' strips on each side o' t' tail o' t' fuselage. Avast! They matched up pretty well, me hearties, matey, me bucko, and t' medium CA gave me enough time t' make sure t' alignment be perfect. Aye aye! I got a pretty solid joint (as I later proved in flight, but more on that later.) Fillets weren't needed, and t' fit covered t' "naked" areas.

I pried t' Mylar tape out o' t' defect in t' external coupler. This left a rougher edge.I glued in t' launch lug.If I had t' do it over, ya bilge rat, ya bilge rat, I would have pulled this off AFTER doin' t' filler step, but BEFORE painting, ya bilge rat, t' get a better look.

Next question, me hearties, where t' attach t' shock cord? If I attached it inside, shiver me timbers, it would get hit by t' ejection charge fairly directly, me bucko, me bucko, and would also cause problem with slidin' out t' motor pod. Avast, me proud beauty! Perhaps more importantly, if it came out t' tail, me hearties, me bucko, t' rocket would fall nose first. Blimey! My launch site is about 3/4 grass, shiver me timbers, me bucko, 1/4 asphalt. Avast! Invariably t' better t' finish on t' rocket, t' more likely it will land on t' asphalt. Also, matey, while t' cardboard/maskin' tape/Elmer's Finish nose cone be holdin' t' finish well, me hearties, I could feel that it was still a little "soft" and didn't think it would hold up t' a hard impact. Finally, me hearties, I figured if I could get t' rocket t' descent in a horizontal position, t' rocket body itself would be addin' t' t' drag and slow it down.

With t' rocket painted, t' CG o' t' rocket body be right at t' region o' t' external coupler. I threaded a needle with me Keelhaul®©™ shock cord into t' tube just above t' coupler next t' t' launch lug, matey, and pull about two feet out t' after end o' t' fuselage. I then threaded a needle with t' ENDS o' a long loop o' dental floss through a hole just BELOW t' coupler and out t' aft end o' t' fuselage. Ya scallywag! I then threaded ANOTHER loop o' floss (loop 2) through this loop, shiver me timbers, and pulled loop 2 through t' hole and out t' tail, shiver me timbers, arrr, me bucko, keepin' t' ENDS o' loop 2 outside fuselage. Aye aye! Begad! I then used loop 2 t' pull t' shock cord BACK into t' tail o' t' fuselage and back through t' hole below t' coupler (there probably is an easier way t' do this, arrr, but this is what I came up with.) I then tied a tight "loop" o' shock cord, me hearties, me bucko, runnin' it just next t' t' launch lug, matey, leavin' about 1 1/2 feet o' Keelhaul®©™ loose. Yes, this loop DID run inside t' rocket body, ya bilge rat, when t' engine pod would slide in and out, but t' cord be runnin' longitudinally and wouldn't obstruct/catch on t' pod. Begad! I did add a bit o' thin CA t' secure it.

Since I wasn't sure how well me hollow nose cone would hold up t' t' Estes engine ejection blast, I cut a bulkhead out o' foam board and place it inside t' body. It slid up t' t' "shoulder" that had been placed on t' front o' t' body tube. Ahoy! Ejection blast would hit t' bulkhead, arrr, me bucko, ya bilge rat, but nay t' "formed" shape inside o' t' nose cone. Instead o' gluin' it into place, I placed a length o' Keelhaul®©™ on this in case I needed t' pull it out later (such as t' add nose weight), shiver me timbers, and left that loose.

Engine Pod: I originally planned t' use a length o' BT20 as an engine mount AND pod. Ahoy! However, after buildin' it, shiver me timbers, I discovered I wanted more room for me parachute and streamer. Ya scallywag! I used a BT20 for an engine mount. Aye aye! Blimey! I then wrapped t' end o' a BT5 with electrical tape until it just fit inside t' BT20. Ya scallywag! T' BT5 acted as BOTH an engine block AND a duct t' direct t' ejection force t' t' front o' t' body, shiver me timbers, shiver me timbers, where it hit t' bulkhead. I used foamboard t' cut adapter rings for t' BT20 at t' tail and t' BT5 at t' front o' t' body. Ahoy! Begad! These were sanded t' slide loosely, shiver me timbers, but hopefully t' front one would be tight enough t' seal t' ejection charges away from t' chute and streamer. Lookin' back, me bucko, I probably should have used two adapter rings up front, ya bilge rat, as a little bit o' ejection charge snuck around t' front rin' and slightly charred t' streamer.

I had initially planned on a long white "simulated TP" streamer t' recover t' rocket (in keepin' with t' theme). Begad! Avast, me proud beauty! Blimey! However, me hearties, early on it was clear that given t' weight o' t' rocket a streamer would never safely slow t' rocket AND t' engine pod. Also, again I knew t' nose cone be a little bit "soft" and wanted t' cushion t' landin' o' t' body as much as possible. Ahoy! Blimey! My solution had two parts. Well, ya bilge rat, blow me down! Blimey! First, allow t' engine pod t' completely separate from t' body o' t' rocket, me hearties, so t' two descend separately. Begad! Blimey! This reduced t' weight o' t' body o' t' rocket (with t' soft cone). Avast, me bucko, me proud beauty! Blimey! If I needed nose weight, me bucko, ya bilge rat, me hearties, I could add it t' t' front o' t' pod, me hearties, rather than t' body. Begad! Avast, me proud beauty! Blimey! This is a NICE trick with aft ejection boost gliders, me hearties, me hearties, by t' way. Begad! Blimey! You can adjust your CG by addin' weight t' t' front o' t' ejection pod, without affectin' t' weight or CG o' t' glider itself. Aye aye! Begad! Blimey! Then I could use me white streamer t' safely recover t' engine pod (which wasn't really very delicate and be nay that heavy), arrr, and a parachute t' recover t' body. T' shock cord for t' body be attached t' OUTSIDE o' t' fuselage at t' CG, ya bilge rat, thus t' body descended horizontally under t' chute.

I used two pieces o' white crepe paper t' create t' streamer for t' body tube. Ya scallywag! I attached them side by side with silver Mylar tape. Begad! Begad! I then accordion folded this into squares t' simulate toilet paper sheets. Begad! T' silver tape showed on one side, which I thought would be easy t' see (on t' off chance this bird flew outside me launch site-- yeah, right.) T' other side was straight white, arrr, which looked like, well, matey, toilet paper. Ya scallywag! Ya scallywag! While for t' real theme this would be "rolled" around t' engine pod "spindle", shiver me timbers, me experience is that this is unlikely t' "unroll" in flight durin' descent. Blimey! Ya scallywag! Therefore I stayed with t' accordion fold. Arrr! I used a length 10 times width, me hearties, ya bilge rat, accordin' t' Stine's book o' optimal streamer length, ya bilge rat, ya bilge rat, then added a couple o' inches t' give me space t' attach it t' t' BT5 section o' t' pod.

I used a couple o' thick rubber bands t' link t' parachute t' t' Keelhaul®©™ shock cord attached t' t' mid section o' t' exterior body o' t' rocket.

Note: Originally I used Tim Van Milligan's Model Rocket Design & Construction book t' make two semispherical parachutes, me bucko, then "ironed" t' two together side t' side. T' idea be t' create a parachute with a "cleft" down t' middle, t' so called "glute chute." (For those who have actually intentionally fallen out o' perfectly good aircraft, matey, thar be a parachute malfunction called a "Mae West" that looks somewhat similar.) However, while t' parachute looked good, the "glute chute" didn't pack very tightly, shiver me timbers, and even reducin' t' engine pod diameter from BT20 t' BT5 didn't give me enough room t' actually use this. Avast! I made an 8-line 12-inch chute out o' a green garbage bag (okay, me hearties, was gettin' tired o' t' theme at this point.)

Construction Score: 2

Flight

Moment o' truth arrived. Blimey! Arrr! Would this work?

First "gotcha" was t' prep. T' overhangin' 4 tube fins may (or may not) look cool. They do however obstruct access t' t' tail o' t' body. Begad! This is bad enough when all you have t' do is stuff an engine in, but when you have t' shove in t' entire engine pod with t' accordion streamer AND t' parachute up t' rear, those overhangin' tubes REALLY get in t' way.

Anyway, me bucko, seemed like a C6-3 engine would probably be a good start for this.

Loaded it up on a nearly windless sunny day. Arrr! Blimey! Crossed me fingers. Well, blow me down! Blimey! Fired. Boost was arced t' t' left (not sure if this was due t' some uneven-ness o' t' fins.) Made it t' roughly 150 feet, at apogee be travelin' nearly horizontal. Arrr! Aye aye! Ejection be at or near apogee. Avast, me proud beauty!

Recovery

Perfect separation o' pod and body. Avast, me proud beauty! Streamer extended nicely and at 36 inches long, 3 inches wide, white and silver, was quite visible. Avast! Arrr! Chute also opened well. Rocket was far away at this point, but t' descent was either horizontal or slightly tail down (just what I wanted, t' protect that nose!) Pod and body landed about 100 yards from pad, about 10 yards apart, me bucko, arrr, ya bilge rat, on t' grass. Absolutely no damage from t' fall. T' white streamer was very slightly singed.

Had I been smart, matey, I would have counted me blessings and put t' rocket on t' shelf at this point. However, ya bilge rat, I'm nay smart. Well, blow me down! I decided t' try it again. Ahoy! On flight two t' engine pod apparently caught on somethin' (may have been packed too tight.) Probably me combined two tubes were nay as smooth internally as a single standard store-bought tube would have been. Begad! Negative ejection. Lawn dart. Blimey! Ahoy! Nay sure any nose cone would have come thought this unscathed, arrr, shiver me timbers, but me (five coats o' filler, me bucko, ya bilge rat, multiple hours o' sanding, multiple coats o' paint - whimper whimper) nose cone accordioned. Blimey! Aye aye! Nay fixable.

Flight Rating: 4

Summary

Pros:

I had fun, probably as much writin' t' background story as buildin' and flyin' t' rocket.
T' paper/maskin' tape/filler nose cone came out well, me bucko, me hearties, matey, and I think I may use this again for aft ejection models (but will start with a REAL body tube!) Also particularly nice for a large but light nose cone. Aye aye! T' nose finishes well and looks great
Rear Ejection worked well. Ahoy! Downsizin' t' central "duct" from BT20 t' BT5 works great and gives you extra space for your recovery device(s). T' BT5 also functions as an engine block. No waddin' required. Arrr! . Well, blow me down! Again, you can use t' long engine pod t' add any needed weight far forward on t' engine pod (and thus anterior on t' rocket in boost phase) to brin' t' CG forward on boost phase without addin' weight t' t' glider at separation.
Separatin' t' pod from t' body allows t' more delicate body t' descend slower.
T' Mylar Mask Strips worked well in allowin' me t' pre-finish and pre-paint parts prior t' assembly, shiver me timbers, shiver me timbers, but still allow a strong joint. Wonderin' if this might work on an Estes Outlander that I have yet t' build. Suggestions would be welcome.
External shock cord attachment at CG allowed model t' descend horizontally. That a horizontal descent position adds more drag on descent is already well known. However it also allowed me t' avoid t' soft nose hittin' ground, which would be t' normal orientation for a rear-ejection model. Begad! This technique may be useful in rockets where certain parts o' more fragile than others. Blimey! Begad! You can adjust t' attachment position t' make it less likely these parts will directly impact t' ground on recovery.
Stayed with Planet Uranus/Toilet Paper Theme
Parts were cheap (until you think o' t' time it takes for extra finishing)
It WORKED! (well, at least once.)

Cons:

Paper/Tape/Filler nose cone is slightly soft. Avast, me proud beauty! It requires a bulkhead t' protect it from ejection charge and should nay be allowed t' directly hit t' ground on descent (especially nay ballistically.)
External Shock Cord is a bit difficult t' stuff into t' engine pod as you stuff t' engine pod into t' tail o' t' body.
Separatin' pod from body on recovery means you must track both (but t' pod falls pretty fast, so shouldn't drift much.)
I couldn't leave well enough alone and stop with one flight.
For some reason t' white paper streamer kept catchin' on me heel.

Overall Rating: 4